Tech Tech Tech, or...So you want to build a trike?

[DeathBySnuSnu]

So I fancy myself as a vw guy. I have had a couple beetles and hot rodded them before. I did move on to big block mopars and did several other things over the years.

So we are going to talk about the type 1 vw.

When you find one it will need work. It is a rare thing to get one used that is "rebuilt" that is actually in good condition. They tend to just be pieced together out of whatever junk parts that can be found. With the absolute minimum done to make it run again just long enough to get rid of.

[DeathBySnuSnu]

The engine case.

Tear it down.
Check the main saddles.
Very common for them to be pounded out.

The original engines were not well balanced and were not intended to rev very high.
It is basically a big lawnmower engine. Just like a briggs is made to crank and run wide open at 3750 rpm all day long, so is the vw.

If there is any visable or feel able damage to the saddles it has to go to the machine shop.
It is called line boring (correct name align bore).
Resize all the saddles and get the bearings that fit.
You can still buy new repop cases and hot rod versions of it.
If you are looking for a used case check other vw groups like "the samba" and the vw facebook groups.
What you are looking for is one of the later cases called an as41 (casting number on side of sump).
It has the most oil controll and improvements made by vw over the years.

[peteg59]

Did VW also have a production/assembly plant in Mexico?
They're pictured a lot down there...Probably buy one in Mex fairly cheap, however getting it across the border & back home might be a challenge.

[DeathBySnuSnu]

So now you have a case to build a motor on.
What do you want out of it?

A well condition stock 1600 dp with its 50 to 60 hp is capable of putting a big smile on your face. Not a ball of fire but still (with a normal rear engine) will do big 1st gear wheelies and cruise the highway at the vw intended rpm.

If your lowly 40 horse spins 3400 rpm at 70 mph.
Then you put a big 2332 full hot rod in its place it will still be 3400 rpm at 70 mph. It will get there quick but not be faster at the same rpm. That is the gearbox's job.

So a lot of the modifications we do to the engine is to increase how high of rpm it can be spun, not just to make more hp at the same rpm.

[DeathBySnuSnu]

Did VW also have a production/assembly plant in Mexico?
They're pictured a lot down there...Probably buy one in Mex fairly cheap, however getting it across the border & back home might be a challenge.

I think (but dont directly know) that there was an assembly plant in Mexico. I think most parts came from the Brazil plant.
But yes Mexico did still have beetles on the road.

[DeathBySnuSnu]

Even though I went overboard with mine....
I dont think we really want a full drag race motor with every high end part available. But also want more than plain stock.

I would not build a motor for myself that was not balanced.
This would mean a counter weighted crank and a trip to the balance shop. It keeps the main saddles intact, extends the rpm capability and is smoother running.
So if you are going to buy a counter weighted crank all the strokes cost about the same. What to choose? Unless you are stuck on a certain displacement there are two clear choices.
74mm because that is how big you can go without machine work.
And 82mm with machine work. Any bigger has cam interference and is more difficult to build.

Cylinder size stock is 85.5
87mm no machine slip ins are good.
88 slip ins are too thin to be durable.
Everything else takes machine work.
90.5 is a good durable size.
92 is sorts thin and borderline durable.
94 takes even more machine work but are more durable than the 92's

So you could build a 1760 with no custom machine work.

Or a 1905 with the 90.5 cyls machining only the cylinder windows.

Or a 2110 with machine work inside and out.

Now the 1776 is a very popular engine.
Stock crank and the 90.5 cylinder.
But without the balance the durability is not improved.

[stinger608]

92 is sorts thin and borderline durable.

This is mostly true, however, they do make the 92mm cylinders that are the same "fly cut" as the 94's which makes them a very durable and tough cylinder set.

These, along with stock 69mm stroke, will give you an 1835 displacement.

If your going for the 1835 setup, don't skimp on the pistons and cylinders and get the set that has the same case bore as the 94's.

If you go with the 94's this will give you a 1914cc displacement.

[DeathBySnuSnu]

I did not think of the thickwall 92's.

Same extra machine work as 94's

Case machined for 90.5 or thin 92's

Same raised lip for cyl to seat on.



Case machined for thick 92 or 94.

Little to no raised edge left so case decked to make new seat face.

The thick 92 and 94 cyls are longer to account for this.

[DeathBySnuSnu]

As anouther note about thick 92's
I had at one time priced them for my build.
Not a lot of choices at that time.
The AA slipper skirt hyper cast were not bad on price but are limited to 6500 rpm.
The AA true forged were not limited but were expensive.

I wound up with forged Mahle light weights but in 94 (no thick 92 in that brand at that time) for actually a lot less money.

Shop around.

[FuzzyWuzHe]

Although I'm not a VW guy, I've owned several bugs and loved them all, I think you guys in the VW forum are awesome ... there is sooooo much info in this forum ... my hat is off to you guys.

[Jester13]

You can buy 1641 jugs and pistons for less than $200.
They will fit either a 1500 or 1600 case.

[Jester13]

Just checked (out of curiosity).
cip1 has them for $159.

I have a couple VWs I plan to do this with.

[stinger608]

You can buy 1641 jugs and pistons for less than $200.
They will fit either a 1500 or 1600 case.

That is very true, however, the 41cc gain really doesn't make all that much of a difference in power.

Really, from 1776 on up with the proper camming and decent heads is really where the Type 1 engines start to shine.

[DeathBySnuSnu]

It is worth doing on a stock rebuild anyway.
41cc aint much and it dont require a big retune of the carb jetting.

As far as shine....
I think stroke is what makes the big difference.

A short stroke 2L motor will make the same peak hp on a dyno as a long stroke 2L motor. Displacement is displacment.

But when you drive it on the street it is the long stroke motor that makes the torque. It will put a smile on your face a lot quicker and pull from lower down. Go to the racetrack and there is not much difference.

[DeathBySnuSnu]

Repost of the bore and stroke sheet.

64 stroke is the 40hp and older engine.

Everything after the 40hp 1200 is related and parts interchange. Some shouldn't be interchanged.

The stroke from the 1300 to 1600 is the same stock 69mm.

[DeathBySnuSnu]

Piston and cylinder kits come in 3 different pin heights. As in the wrist pin to the top of the piston dimension is defferent.

A stroke p&c kit is stock pin height.

B stroke p&c kit is the stroker pin height.

C stroke p&c kit is for extreme strokes 86 and larger.

You wont see a C kit listed very often unless you like to look around the super high dollar mega race sites where they sell the billet drop cam engine cases and want to run a set of super squishies.

[DeathBySnuSnu]

Stroker motor info.

[Loner]

Every day I anticipate the new installments being collected here for our knowledge library. The deep technical info is amazing and helpful to all levels of trike builders and particularly us VW fanatics. I am considering what contributions I might bring to the table rather than just wait to be spoon-fed the new tech, tech, tech . . . . data. I am pondering a couple of questions as to the plans for this reference collection:


First, is there a plan to organize these tech resources into some cataloged or categorized grouping? That would allow members to access particular areas of interest effectively as their needs dictate. As it grows, we may perhaps could find a way to add search capabilities or other shortcuts.


Second, I think . . . Snu's Title for this thread is prophetic as he presents "tech, tech, tech . . . " and then "So you want to build a trike?". As I read the technical info provided, I am wondering if the two elements might warrant two separate collections this early in the game. The tech thread ongoing is building truckloads of excellent topical tech data. I am thinking (that's where I usually get into trouble) that a second thread could concentrate on data and guidance for building a VW trike from when the little light bulb goes on to the first shakedown cruise and beyond. That thread could look at the diverse levels of tech capabilities that folks have to put together a trike. Perhaps a basic approach to concept, design, fabrication, etc. providing an outline of possibilities and then referring to the tech thread/library for topical areas of the build process.


That plan/layout/build process thread could offer info on alternative approaches and considerations in trike building. Such as a major approach up front as to whether you design around what you want and then go get your parts to accomplish that or do you have a VW that you want to use for your trike. In the latter instance we could provide assistance in how to best utilize what he/she has, while in the previous case (design and then find components to fit) the builder has a broader palette such as build a complete frame (no VW suspension robbed from a car) vs. build a frame using VW suspension components. Even then we could inform the builder about options such as using a Type 3 subframe which is basically a bolt-in rear suspension that could simplify a trike frame.


I am getting too deep into examples, but I think I've thrown something out for consideration. If our lead Gurus prefer, I will be quite happy to continue to soak up (and hopefully contribute to) the ongoing tech thread advancements. That thread strikes me as a pot-of-gold for us techies.

[DeathBySnuSnu]

Some organization has been mentioned before.

My thought just sorta ramble around here and there when I am the only one talking.

I did expect more questions and expounding a detail further to someone.

I have been real happy lately with a couple others posting up stuff learned and adding to the tech.

And the type 3 sub. It is the most viable way to go to a full automatic trans.

[Papa Zook]

Great feedback Larry, Rex & Dano. I have added this as a featured thread. I will be happy to help format this however you guys want, I'm open to suggestions. We can start a small group to discuss ways to format this so we dont derail this thread. Look under community and groups in the navigation bar for VW Tech Group.

edit: invitations sent